The current standard of care in the treatment of the severe behavior disorders of individuals with developmental disabilities relies on (1) identifying the environmental variables that give rise to and maintain (reinforce) the problem behavior and (2) arranging for the relevant reinforcers to be delivered in a manner that displaces their procurement through problem behavior. Noncontingent reinforcement (NCR) is a therapeutic arrangement, based on this model, in which the reinforcer hypothesized to maintain a problem behavior is delivered on a response-independent, time-based schedule. This form of intervention has grown increasingly popular over the past decade, its popularity largely driven by its ease of implementation relative to other common interventions and demonstrated effectiveness in decreasing problem behavior during protracted evaluations and under limited circumstances. However, NCR may have unknown detrimental effects under arrangements that go beyond the typical treatment evaluation, often predicted by research on basic behavioral process that has yet to fully come into contact with the treatment literature. This proposal describes an exploratory, translational project designed to evaluate the impact of these basic behavioral processes (behavioral momentum, hedonic constrast, and behavioral reinstatement) on interventions built upon the noncontingent delivery of reinforcers. Specific studies will determine the extent to which NCR enhances the resistance of problem to other forms of intervention, produces an increae in levels of problem behavior in non- treatment settings, and reinstates probelm behavior that had previously been reduced through other forms of intervention. These questions will be answered through a series of comparative treatment evaluations in which the effects of NCR will be compared with the effects of parallel interventions that rely on the contingent reinforcer delivery or more simply, the absence of free reinforcement. The proposed studies will form the basis of a larger objective to determine the optimal therapeutic arrangements for this and related interventions. Thus, the outcomes have significant potential to impact treatment selection for individuals that display severe behavior disorders. 7. Project Narrative Noncontingent reinforcement (NCR) is an increasingly common intervention for the severe behavior disorders of individuals with developmental disabilities. However, certain basic behavioral processes, yet to be examined in a clinical context, predict that NCR may increase behavior problems when it is not being directly implemented or may weaken the effects of other interventions. This project will determine the extent to these side effects occur as a first step towards determining how they can be avoided. [unreadable] [unreadable] [unreadable]